The long-term objective of the proposal is to establish the pharmacological rationale for the use of different types of drugs in the treatment of atherosclerotic vascular disease by determining their effects on the pathophysiology and biochemical pathology of experimental atherosclerosis in subhuman primates. We propose to investigate the anti-atherosclerotic effects of two major groups of drugs in the cynomolgus monkey with pre-established atherosclerosis. These include penicillamine and colchicine (inhibitors of collagen biosynthesis) and dichloro-methyl-diphosphoric acid (Cl2MDP) and p-amino-hexadecyl-benzoic acid (PHB) (anticalcifying drugs). The effects of these drugs on the extent and severity of atherosclerosis will be evaluated at necropsy from the morphological and biochemical findings in the coronary and peripheral arteries.